Apparatus for polishing or forming facets on gems, diamonds, or the like



Ja:n. 29, 1946.

J. H. SPIRA 2,393,939 APPARATUS FOR POLISHING OR FORMING FACETS DIAMONDS, OR THE LIKE 51, 1942 2 Sheets-Sheet 1 ON GEMS,

Filed Mqrch A TTORNEY Patented Jan. 29, 1946 APPARATUS FOR POLISHING OR- FORMING FACETS ON GEMS, DIAMONDS, OR THE LIKE Josef Hillel Spiro. New York. N. Y.

Application March Braslllidarch 31,

31, 1942. Serial No. 431-058 8 Ciahns. (Cl- 51-229) This invention has as its object the provision of apparatus for grinding or cutting the facets u-pon gems, or what is generally referred to as the polishing of gems, particularly diamonds. which hitherto largely have been worked successfully only by manual labor, which required unusual skill and experience.

The present invention has for its object the grinding or polishing of the facets on gems by semiautomatic means which minimizes the extraordinary skill heretofore necessary, and the provision of a new and novel method.

The present invention makes possible a faster production of the operations for finishing these gems, requiring less skill than the heretofore known methods, and makes possible the effecting of considerable economies involved in carrying out these hitherto highly expensive and laborious operations.

Heretofore the method of forming the facets upon gems has been under the strict supervision of a skilled worker who ascertained the accuracy of his work by constant inspection, which was dependent upon the skill acquired through many years of experience.

In the present invention, in order more economically to increase production and largely to eliminate the element of unusual skill, and provide semi-automatic devices for accomplishing the desired end, I have departed from the age-old and obvious procedure in polishing gems. particularly diamonds, with a consequent simplification of this laborious procedure.

More particularly, my invention contemplates the provision of a dop for facetting or polishing the pavilion facets by merely mechanically clamping the bezel forming portion of the bruted stock in its unfinished state, eliminating the necessity for using cement, solder, or the release of the diamond in progressing from one facetting position to another.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, I make reference to the accompanying drawings, forming a part hereof, in which:

Figure 1 is an enlarged fragmentary sectional view of the work holder or dop, and the mounting assembly therefor;

Figure 2 is a front elevation thereof;

Figure 3 is a section taken on the line -5 of Figure 2:

Figure 4 is a fragmentary side elevation of the reverse side of Figure 1;

Figure 5 is a plan view of the disassembled work holder or dop;

Figure 6 is a fragmentary sectional longitudinal view thereof, taken on the line 9-0 of Figure 5; Figure 'l' is a face view of the work holder or dop. with an adapter, and the gem in position:

Figure 8 is a fragmentary sectional view taken on the line ll-Il of Figure I.

It is contemplated by my invention to provide the raw stock with a table section and a pavilion or base section. The base section is mounted in a work holder or dop to expose the pavilion or base. 'I'l'iis pavilion or base is first formed with the facets arranged pyramidally thereon. in sufficient number to provide an axially accurate system in respect of the table so that the facets of the pavilion are symmetrical to the table and the axial line through the pyramidal section is at right angles to the table. Thereupon, the pyramidall facetted pavilion serves as the means for axially rotating the gem to expose the crown or bezel, and polish the crown or bezel with the requisite facets.

The sequence of steps in accordance with my method enables me quickly and facilely to perform the polishing or faoetting operations more economically and by semi-automatic apparatus, thereby to minimize the requirement to use unusually skilled operators.

I will now make reference to the drawings forming a part hereof in which novel apparatus has been devised by me to facilitate the practice of my method.

The circumferential formation of the facets about the work will more clearly appear in, connection with the description of details of the work holder ill, by reference to Figures 1 to 8, which represent the work holder or dop for polishing the pavilion facets.

The work holder or dop it constitutes a cylindrical shell 89. to which is afflxed the spaced arcuate bearing 1'4 adiustably supported by a corresponding bearing 12 of the machine. Ad- Jacent the end iii. a set screw II serves to releasabiy engage the revoluble assembly 92 shown in Figure 2.

Referring now to Figure 2, there is provided a tubuar element or sleeve 9!, having a bearing portion 84 carrying a collar 95. Beyond the bearing portion 94 the sleeve 93 is screw thereaded at 90. A shell 91, having a flange BI, is screw threaded to engage the screw threaded section 88. Pin wrench holes 99 are used to rotate the sleeve 91 about the member 93.

The sleeve 01 is recessed at I. Within this recess there is mounted an inner sleeve Ill, having a screw threaded section III, adapted to ens-c the screw threaded section it previously mentioned.

The section I42 is formed with pin wrench oriflees III. The pin wrench oriiices I 03 are accessible through the slot I04 formed in the flange abutting the sleeve 01. The tubular element or sleeve 08 is sliti'ed at I05 to provide oppositely faced sections l0l-I0li and I01I01 see Figures 5 and 7. These sections form resllient segments I08 of generally cylindrical contour, merging into conically shaped protuberances III, the base of which may freely enter the sleeve 00.

Beyond the base IIO. the sections I08 and I01. respectively, are tapered to form the nose III, receding from the orifice H2. The sections I00, adjacent the shank I08 thereof, are formed with clearance slots II3 opposite to the edges "4 of the inner sleeve III. The sections I01 are formed with clearance slots II! adjacent the rim IIO of the outer sleeve 01.

Since the rims H4 and H0 are conically shaped, it will be appreciated that withdrawal of the tubular section 03 in relation to the sleeves l1 and III will serve to bring the sections IIO-IIII toward each other, and bring the sections I01-I01 towards each other, to reduce the size of the aperture III.

Where, as in the preferred embodiment, the sleeve Ill bears against the sections I01, and the sleeve 01 bears against the sections I 06, it will be understood that independent movement of these sectionalized elements is obtained to secure accommodation to any irregularity in size of any work which may be placed in the orifice H2. The tubular section 92 is formed with a boring "1 which has a shoulder H0, thereby providing the enlarged boring corresponding to the opening II 2. Within the opening II2 there may be disposed an adapter shell IIO, one end whereof I20 abuts the shoulder H0.

The shell H8 is slitted at I2! for a portion of its length to provide pairs of sections I22, I28. When the adapter is placed in position, the slits I2I are arranged to be coincident with the slits i". In this position segments I08-I08 will move segments I22-I22, and segments I 01-I0I will move segments I2l-I23.

The segments I22I22 and the segments I2lI23 are nosed substantially to correspond to the taper of the nose III. The work 85 may be held by the adapter shell II! by the nosed portions I22-I22 and the nosed portions I20-I23. The adapter shell may be made with an orifice I24 to take care of the size of the work. Graded sizes of these adapters may be provided, each fitting within the orifice II2 but having the nosed portions varied, to vary the size of the orifice I24.

The side walls I25 defining the orifice I24 are preferably cylindrically formed to correspond to the cylindrical section I28 of a bruted work piece 85. This work piece has the table section i21 directed within the orifice I24. Into this orifice there is extended a backing rod I28, the diameter of which at the point of contact with the table face I21 of the work 85 corresponds closely to the diameter of the orifice I24 of any selected adapter. Thus. with graded sizes of adapters as above mentioned, there is provided for each adapter an appropriate backing rod having the face I2! thereof dimensioned to suit the size of the associated adapter orifice I24.

The face I 20 of the backing rod I20 is'incon" tact with the table face I21 of the work 68, thereby eii'ectively preventing the work It from tilting. and cooperates with the cylindrical portions I25 which define the opening I24 to hold the work 8| in accurate axial alignment, with the table face I21 perpendicular to the axis running through the work holder.

The rod I20 extends into the boring II1 beyond the upper end I30 of the sleeve ll. The rod I20 has its upper end III preferably tapered.

With the assembly as provided, I first dispose a spring washer I32 over the collar 05 and then amx a cap I in screw threaded position thereover. A threaded collar I34 serves to lock the cap in relatively fixed engagement with the sleeve 02. Sleeved over the end I10 01' the section 08, I provide an adjusting cap I05, which is screw threaded and has a tapered bearing I30 bearing against the end I of the rod I20.

It will thus be seen that rotation of the adlusting cap III will serve micrometrically to feed the backing rod I28, and therefore micrometricaliy feed the work 05 within the oriflce I held between segments I22-I22, Ill-I23. A lock nut I350 is provided for the cap Ill. The entire assembly 02 illustrated in Figure 2 may then be sleeved within the sleeve 0!, whereupon the set screw ll is driven home to engage the collar 05.

The upper edge I01 of the sleeve 00 is cylindrically shaped to receive the collar I80, which is sectionaliaed at I30 to receive the set screw 9|, previously referred to. The collar III may be rotated or it may be given a fixed position by the footed member I40. held in position by the set screw I. The collar I20 carries a reference or zero marking I42 in close proximity to the periphery of the cap III, which carries a series of graduation marks I42 for indexing the work. These graduation marks are designed to indicate a fraction of a complete rotation. The number oi graduations correspond to the number of facets which it is desired to form upon the work. Graduations of eight and sixteen are those customarily employed. They may be increased in number for brillianteering.

To begin the work the zero marking I42 is first adjusted after releasing the set screw I4I, after which adjustment, until the particular gem is completed, the reference marking I42 is held stationary or fixed by tightening the screw I".

In operation, in connection with the formation of the facets on the pavilion or base, one facet is formed and at the completion thereof, the work holder is re-set by turning the cap I to the new position.

The work holder illustrated in the drawings is employed to form the bottom comer and pavilion and culet facets below the" girdle of the gem, as an initial operation, by the adjustment provided by the arcuate suspension for the work holder 13 and the revoluble adjustment of the work holder within the sleeve 00.

Upon the completion of the facets below the girdle, a truly pyramidal arrangement of the facets is secured in relation to the axial line through the gem, perpendicular to the table formin portion I21. The gem may thereupon be removed to the dop or work holder for forming the crown or bezel facets.

In this construction, a sleeve I50 is provided with spaced arcuate bearings Iii-Ill, corresponding exactly to the spaced arcuate bearings 14 in the preceding views for reception upon the arcuate guides 12-12 carried by the block 31.

The sleeve IE0 is formed with a boring I52,

which is screw threaded at I53 adjacent the end III. I thereupon provide a shaft I65, adjacent one end I58 whereof there is formed a cup itl defining a rim I58. which is provided with a sharp edge I59. The cup I" is arranged to receive the pavilion engaging adapter I80, which comprises a shank llii of cylindrical contour, making a close fit with the cup lil. A fiange I82 engages the pointed rim I. The pavilion engaging adapter llll is of conical form, and terminates at its apex I68 adjacent an axially formed orifice I, defining a seat lil where the walls of the orifice I64 merge with the apex I.

The slope of the conically formed adapter I" is calculated to be less than the angle of any bezel facet which terminates at the girdle of a gem, in relation to the axial line through the gem, thereby providing adequate clearance in the formation of the facets above the girdle in the crown or bezel forming portion of the gem.

It will thus be observed that I have provided novel apparatus for minimizing the labor and unusual skill in connection with the gem polishing or facet forming art, whereby these steps may be performed by semi-automatic procedure. It will also be observed that apart from the features included in utilizing all of the assembly, I have provided apparatus. details whereof have utility independently of the entire assembly, as will be appreciated by those skilled in the art, and accordingly, the invention should be broadly. as well as specifically, evaluated.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent, is:

1. In a device for forming facets upon gems, a pavilion dop therefor to hold the gem angularly to a skeif surface and for positioning said gem for forming the pavilion facets by holding the cylindrical bezel forming portion of the gem in an unfinished state before imposing the bezel facets comprising a stem having adjacent one end at least three jaws grouped radially to provide an interior bezel engaging surface substantially of cylindrical contour, said jaws having at their exterior terminal portions conical protuberances merging into tapered sections cooperating to form a tapered nose, an axially disposed backing rod adjustable in said stem to provide a variably positionable seat within said cylindrically contoured portion of said jaws and a sleeve about said laws for engaging the conical protuberances of said jaws, means for adjusting the sleeve longitudinally of said jaws to draw them together radially to clamp the gem, a holder for the dop, indexing means for said stem cooperating with said holder to index said dop in different faceting positions.

2. In a device for forming facets upon gems, a pavilion dop therefor to hold the gems angularly to the skeif surface for forming the pavilion facets by engaging the cylindrical bezel forming portion of the gem in an unfinished state before making the bezel facets, comprising a tubular stem having at one end at least three integrally formed, resilient, stone-engaging fingers, grouped radially to provide an interior bezel engaging surface substantially of cylindrical contour, a sleeve having camming action on said fingers to cause the fingers t6 be flexed to bring them toward one another, means for moving said sleeve for adjustment in relation to said fingers on the stem, and an axially disposed backing rod, one end of which is positioned adiustably between said fingers and forms a seat for said gem by engaging the table portion thereof and hem! encircled by said fingers to clamp the cylindrical bezel forming portion of the gem stock against displacement wholly to one side of the girdle of the gem, a holder for the dop, indexing means adjacent the opposite end of said stem, cooperating with said holder to index said dop in different facetlng positions whereby all of the facets of said pavilion forming portion of the gem may be polished successively simply by indexing from one facet to another. without disengaging the gem from the fingers or the dop.

3. In a device for forming facets upon gems, a pavilion dop therefor to hold the gems angularly to the skeif surface for forming the pavilion facets by engaging the cylindrical bezel forming portion of the gem in an unfinished state before making the bezel facets, comprising a stem having more than two integrally formed, resillent, stone-engaging fingers, grouped radially to provide an interior bezel engaging surface substantially of cylindrical contour, a sleeve having camming action on said fingers to cause the fingers to be flexed to bring them toward one another, means for moving said sleeve for adjustment in relation to said fingers on the stem, and an axially disposed backing rod. the end of which is positioned adjustably axially of said fingers and forms a seat for said gem engaging the table portion thereof and being encircled by said fingers to hold the cylindrical portion of the gem stock against displacement wholly to one side of the girdle of the gem, a mounting member for rotation of said assembl including indexing means whereby all of the facets of said pavilion forming portion may be polished successively simply by indexing from one facet to another, without disengaging the gem from the fingers or the dop from the mounting member therefor.

4. In a device for forming facets upon gems, a pavilion dop therefor to hold the gem angularly to a skeif surface, and for positioning said gem for forming the pavilion facets by holding the cylindrical bezel forming portion of the gem in an unfinished state before imposing the bezel facets comprising a stem having adjacent one end at least two pairs of opposed jaws grouped radially to provide an interior bezel engaging surface substantially of cylindrical contour, said jaws having at their exterior terminal portions conical protuberances merging into tapered sections cooperating to form a tapered nose, an axially disposed backing rod adjustable in said stem to provide a variably positionable seat within said cylindrically contoured portion of said jaws and separate sleeves about said jaws, each sleeve having means for engaging independent pairs of the conical protuberances of said jaws, means for independently adjusting the sleeves longitudinally of said jaws to, draw them together radially to clamp the gem, and a holder for the dop, indexing means cooperating with said holder to index said dop in different facetting positions.

5. In a device for forming facets upon gems in accordance with claim 1 wherein said backing rod extends through said stem rearwardly to said opposite end, and is provided with means adjacent said latter end to feed the backing rod axially between said jaws.

6. In a device for forming facets in accordance with claim 1 wherein said jaws carry an adapter comprising a slotted spring sleeve divided into sections formed with tapered ends substantially corresponding to the tapered sections of said jaws.

7. In a device for forming facets in accordance withclaimi whereinsaldiawsearryanadapter eomprisingasleeveslottedtoprovideatleasttwo pairs of opposed Jaws, actuated to clamp said gem by said first laws.

8. In a device for forming facets upon gems, a pavilion dop therefor to hold the gem angularly to a shelf surface and for positioning said gem ior forming the pavilion facets by holding the cylindrical bezel forming portion of the gem in an unfinished state before imposing the besel facets comprising a stem having clamnins Jaws adjacent one end, grouped radially, said laws each having a camming portion, a sleeve having camming action on said jaws to cause said Jaws to be brought toward one another, means for moving said sleeve for adjustment in relation to said jaws on the stem. an adapter carried and clamped by said jaws comprising a slotted spring sleeve divided into at least three sections, with tapered ends to form a tapered nose, providing resilient stone enga n fin s. o p d radially to p ovide an interior bezel enga ing surface substantially of cylindrical contour, an axially disposed backing rod adjustable within said adapter to Certificate oi. Correction Patent N 0. 2,393,939.

January 29, 1946.

J OSEF HILLEL SPIRA It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Pa

e 1, second column, line 46, for

"tubuar read tubular; page 2 second column, line 70, e 'nning with "In this construction strike out all to and including the word and perio gem., page 3, first column, line 20; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the casein the Patent Oifice.

Signed and sealed this 21st day of May, A. D. 1946.

[snap] LESLIE FRAZER,

First Assistant Omnmissiomr of Patents.

withclaimi whereinsaldiawsearryanadapter eomprisingasleeveslottedtoprovideatleasttwo pairs of opposed Jaws, actuated to clamp said gem by said first laws.

8. In a device for forming facets upon gems, a pavilion dop therefor to hold the gem angularly to a shelf surface and for positioning said gem ior forming the pavilion facets by holding the cylindrical bezel forming portion of the gem in an unfinished state before imposing the besel facets comprising a stem having clamnins Jaws adjacent one end, grouped radially, said laws each having a camming portion, a sleeve having camming action on said jaws to cause said Jaws to be brought toward one another, means for moving said sleeve for adjustment in relation to said jaws on the stem. an adapter carried and clamped by said jaws comprising a slotted spring sleeve divided into at least three sections, with tapered ends to form a tapered nose, providing resilient stone enga n fin s. o p d radially to p ovide an interior bezel enga ing surface substantially of cylindrical contour, an axially disposed backing rod adjustable within said adapter to Certificate oi. Correction Patent N 0. 2,393,939.

January 29, 1946.

J OSEF HILLEL SPIRA It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Pa

e 1, second column, line 46, for

"tubuar read tubular; page 2 second column, line 70, e 'nning with "In this construction strike out all to and including the word and perio gem., page 3, first column, line 20; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the casein the Patent Oifice.

Signed and sealed this 21st day of May, A. D. 1946.

[snap] LESLIE FRAZER,

First Assistant Omnmissiomr of Patents. 

